Primordially, the correction of teeth position was realized by forward influences of active details of removable orthodontic devices on teeth that was carried out by periodic removal of the device, restoration of its decreasing influences and its fitting in a cavity of a mouth.
In the beginning of the 20th century, Mershon and Crozat have developed devices allowing to carry out forward influences simultaneously on lingual surfaces of lateral and frontal teeth (see, “Directory on orthodontics”, Kishinev 1990, page 180, FIG. 27 and page 188, FIG. 28).
At about the same time, Ainsworth designed a device, carrying out forward influence respectively on lingual and vestibular surfaces of lateral and frontal teeth (see, Kolesov “Stomatology of childhood” Moscow 1970, FIG. 106).
Today, the advanced removable devices of forward influence—appliances of Crozat-Ricketts and Wilson, are widely used in practice (see, respectively “CONSUMMATE OCCLUSION” R. Ricketts 1996, FIGS. 2-7 and “ENHANCED ORTHODONTICS” R. Wilson, W. Wilson, page 55).
The above-described devices carrying out a method of periodic activation and influence on teeth by forward forces allow to achieve correction of teeth position and form of dental arch. However, the expansion and lengthening of a dentition by the above-mentioned method results in a buccal (vestibular) inclination of teeth, that is, corpus (bodily) shifting of teeth is not provided.
In 1886, Angle, the founder of modern nonremovable orthodontic equipment designed a device of forward influence, which is nonremovably fastened on vestibular surfaces of teeth.
In 1916, for the first time he offered a method of influence by forward-rotary forces, carried out by the fixed arch device, providing corpus (bodily) shiftings of teeth. Subsequently, Angle, through improvement of a design of nonremovable orthodontic device for forward-rotary influence on teeth, has executed it in the form of arches fastened in locks, rigidly fixed on teeth. A method and devices, developed by Angle, have allowed achievement of a corpus (bodily) shifting of teeth and correction of the form of dental arch. (see, “CONSUMMATE OCCLUSION” R. Ricketts 1996, FIGS. 2-5B and 2-6A).
However, for high-grade deformations of a dental alveolar arch, achievement of corpus (bodily) shifting of teeth in vestibulolingual directions through influence of forward-rotary forces on them by fixed arch devices is possible to realize only after preliminary correction of geometry of dental arch and alignment of teeth.
As a rule, the mentioned preliminary correction is carried out by removable or nonremovable devices of forward influence, which are mounted in an oral in the initial stages of treatment. This means that the process of correction of a dental alveolar arch is multistage, and the forward-rotary influences on teeth by nonremovable arch devices are carried out at later stages of orthodontic treatment.
As is well known, the movement of teeth in an alveolar process is possible due to the coordinated processes of resorption and regeneration (apposition) of an alveolar bone. Moreover, the surface of alveolar process faced to a root of tooth in places of squeezing and tension of walls of bone-medullar cavities is periodically subjected respectively to resorption and apposition.
The application of large forces in nonremovable arch devices can result in resorption of not only alveolar bone, but roots of teeth too, therefore in practice, small forces are used more often. Summarizing the above-mentioned, it should be stated that nonremovable arch devices do not ensure intensive correction of the form of alveolar process and require a long-term treatment.
For elimination of staged treatment at the high-grade deformations of a dental alveolar arch, the removable designs of orthodontic devices providing forward and rotary forces on teeth were offered. Devices of the given design constitute the metal wireframes on dentition's segments, which are dispersed along the height of teeth and connected with each other by orthodontic arches and/or springs (see the invention patent of the Republic Armenia No. 512, IPC A61C7/00, 1999, and applications for the inventions of the Republic Armenia No. 20050147, 20050148, 20050149 IPC A61C7/00, 2005). The above-described devices were applied by a method attributable to removable devices—by periodic removal of the device, restoration of decreasing influences and its fitting.
Such a method of treatment with the specified devices is favourably distinguished from known subjects, that at significant deformations of a dental alveolar arch, it allows to exclude multistage nature of a treatment and to achieve forward-rotary influence on all teeth in the necessary direction. Regardless of the fact that during the use of these devices the generally accepted in orthodontics values of forces on crowns of separate teeth of 50-150 gm were applied, torques on root apexes of teeth exceeded similar values provided by other devices of forward-rotary influence in several times. It is stipulated by that the fastening metal wireframes with elements, dispersedly mounted along the height of teeth's crowns, at realizing of rotary influence on teeth provide the maximum large arm of applied forces and promote the increase of torque on roots of teeth. The above-mentioned property allows movement of an axis of rotation of teeth to the root apexes and, consequently, to create zones of a tension and squeezing of an alveolar bone, which are adjacent to the lingual and vestibular surfaces of roots of teeth. Depending on an axial position of teeth, the value, sequence and combination of applied forward and rotary forces on them are adjusted during their movement. The application of the above-mentioned method and devices provides a corpus (bodily) shifting of teeth and a simultaneous growth of an alveolar process dimension, with the intensity of about 0.3-0.4 mm/months. However, in the result of long-term influence of elements of fastening metal wireframes, mounted in interdental spaces, the teeth are influenced by the forces pushing out of them from the alveolar sockets that results in loosening of separate teeth.